The lever has a decently stiff spring on it. I've always carried mine in a cooking pot and never had a problem - no unexplained use or loss of fuel.
While I'm fine with one knife, one pair of shoes, and one hat, I do bring two sources of ignition. Mini Bic and a flint; Mini Bic and a book of matches; or two mini Bics. Yeah, you can always rub two boy scouts together, but starting a fire instantly is SO convenient and at times aids one's safety so much, I splurge on the extra 15 grams.